Feed mechanism for drilling machines and the like



June 30, 1931. w. P. HUNT 1,812,533

FEED MECHANISM FOR DRILLING MACHINES AND THE LIKE Filed Oct. 17, 1929 91 m 7P7 .5 BY.

M ATTORNEY Patented June 30, 1931 UNITED STATES PATENT OFFICE WILSON P. HUNT, OI HJOLINE, ILLINOIS, ASSIGNOB '10 MOLINE TOOL MOLINE, ILLINOIS 1mm) uncn amsu ron nmnmno uaonnms Ann'rnn mxn Application filed October 17, 1929. Serial No. 400,232.

My invention has reference to a feed mechanism for drilling machines, and other'machines of that character, and relates more speciall to means for controlling the movement 0 the tool or other part, so that it will conform readily to variations in. the character of the piece of work that is being operated upon. A similar device is set forth in a former a plication for Letters Patent of the United tates, filed by myself on the thirtyfirst day of May, 1929, Serial No. 367,330. Said former application included a feed cylinder, for the use of compressed air or similar force for moving the art to be transported, a secondary cylin er containing a non-elastic controlling element, and an a dditional container, or tank, connected with said secondary cylinder, and permitting a variation in the amount of said controlling element under varying operating conditions. In the present invention one of the cylinders is done avlggyd with, and thedevice considerably sim- P The operation of the invention is largely similar to that of the machine shown in said former application, the tool being given a relatively rapid movement until the piece of work is encountered thereby, following which there is a more deliberate movement thereof, the tendency of the tool to move fastor or slower being imparted to the control (Element, and receiving a quick response thererom.

The particular construction, arrangement, and operation of the various parts of the invention will more fully appear from the following specification, taken in connection with the accompanying drawing, showin the invention in elevation, with some of e parts in vertical medial section.

The reference number 1 indicates a cylinder, fitted with an upper end-plate 2, and a lower end-plate 3. In the end-plate 2 is slidable a rod 4, provided at its lower end with a piston 5, having a central packing ring 6, fitting snugly in the inner wall of the cylinder. On the upper end of the rod 4 is a series of teeth 7, in mesh with the teeth of a pinion 8, fixed on a shaft 9, which has a rotatable mounting, not shown in the drawing. The

pinion 8 is also in engagement with the teeth 10 onv a bar 11, to the lower end of which is fixed an arm 12, in the other end of which is rotatably supported a spindle 13, to the lower end of which is secured a drill 14. The

mechanism by means of which the spindle 13 is rotated is of a well-known type, and is omitted from the drawing. The movement of the rod 4 in either direction operates to move the bar 11 in a contrary direction, to 0 the same degree. Communicating with the cylinder 1 through the end-plate 3 thereof is a pipe 16 through which an operating fluid or liquid may be introduced under pressure to that part of the cylinder which is beneath the piston 5. The pipe 16 is connected with a supply pipe 17 through avalve casing 18, containing a valve of a common three-way type, under the control of a hand-lever 19. Movement can thereby be imparted to the rod 4 in a direction to cause a downward feed of the rod 11 and drill 14.

. Supported at a little height above the cylinder 1 is a tank 20, in communication with the cylinder 1 by means of a pipe 21, one end of which passes through the end-plate 2. Cut in to the pipe-21 is a housing 22, containing a valve chamber 23, the upper end of which communicates with the tank 20 through a pipe 24. One end of the pipe 21 communicates with the tank 20 through a needle-valve fitting at 25. Within the chamber 23 is a valve 27, on the lower end of a rod 28, the

upper end of which has a pivotal connection with a cam-lever 29, pivoted at one of its ends to a fixture at 30. Fixed to the rod 4 is an arm 31, carryin a roller 32, adapted for engagement with t e edge of the cam Y29 and the extension 33 thereof.

The upper part of the cylinder 1, above the piston 5, is designed to contain a quantity of oil or other non-elastic medium, which, upon the upward movement of the piston 5, is forced upwardly into the tank 20. At the beginning of this movement the valve 27 is in the lower part of the chamber 23, permitting a comparatively rapid escape of the liquid through the pipe 24 into the tank. This permits a correspondingly rapid movement of 1G the rod 4 upwardly, and of the rod 11 and tool 14 downwardly until the tool comes in contact with its work, at which time thecam lever 29 is elevated by the arm 31, closing the valve 27 against the outlet to the pipe 24, and turning the flow of oil through the longer branch of the pipe 21; The movement of the oil through this pipe and thefitting 25 is controlled by means of a needle-valve 34, on I the lower end of a rod 35, which extends upwardly through the tank 27, and above the same, to a connection with a governor apparatus of a common type, shown at 36. Included in said governor apparatus is a worm drive 37 in mesh with a worm-gear 38 on a flow of the li uid through the valve. This valve is norma y open to such an extent as to permit a continued movement of the tool after it encounters the work, but at a greatly reduced rate of speed, and in the event ofthe tool entering a soft spot or pocket in the metal, with a tendency to feed more rapidly, the valve responds at once to this impulse, retarding the flow of the control medium, and keeping the tool at a uniform rate of speed.

'During the continued upward movement of the rod 10 the roller 32 is in contact with the extension 33, holding the valve in position to keep the pipe 24 closed. Upon the work of the tool being finished the valve at 18 is turned to permit an exhaust of the air in the lower part of the cylinder 1, and at the same time permit a movement of the operating fluid from the pipe 17 through a pipe 40 to the upper end of the tank 40, tending to force the control medium in said tank back into the cylinder 1, moving the piston therein downwardly, and returning the drill 14 to its original position. This movement is assisted by the weight of the oil in the cylinder 1 and tank 20.

It will be obvious that in the cycle of movements of the machine hereinbefore set forth the tool will approach the work at a rapid rate of speed, which will be reduced and automatically controlled upon the tool coming in contact with the work, and that upon the com-1 letion of the special operation of such tool 1t will bereturned at once to position for another operation.

In the operation of drills and similar tools the work'is usually supported upon some sort of a base or table, and in cases where it is desired to have the tool held in a stationary position, and the work moved toward or from the same, the present invention can be employed for operating the work-bearing table, and controlling the movements thereof. Changes can also be made in the general construction of the machine and the manner of operating the same, and continue within the scope of the invention.

What I claim, and desire to secure by Letters Patent, is:

1. In combination with a tool organism ineluding a tool to be carried thereby, a cylinder, a piston in said cylinder, a piston-rod for said piston, operatively connected with said tool organism, means for introducing a fluid force on one'side of said piston, an auxiliary container in proximity to said cylinder, and united therewith by passages of varying capacity, means .for closing the larger of said passages, means carried by said piston-rod for actuating the last-named means at the end of a predetermined movement of said rod, a fluent non-elastic medium contained in said cylinder on the opposite side of the piston from the fluid force, and releasable into said. auxiliary container through said passages, and means for controlling the release of said medium automatically from the movement of said tool organism, through the smaller of said passages.

2. In combination with a tool orgamsm in-.

cluding a tool carried thereby, a feed mechanism for said tool organism comprising a cylinder, a. piston therein, a rod for said piston operatively connected with said tool or-. ganism, means for supplying a fluid elastic force to said cylinder on one side of the piston, an auxiliary compartment in proximity to said cylinder, a pair of conduits connecting said compartment with said cylinder, on the opposite side of the piston from said force, one of saidconduits being of a relatively limited capacity, a fluent non-elastic medium in said cylinder, releasable through said conduits into said auxiliary chamber, a valve adapted to close the larger conduit and means for closing the same upon the piston rod reaching a predetermined point in its movement, a valve for the limited conduit, a governor mechanism connected with said last-named valve, for the control thereof, and connections between said governor mechanism and said tool organism, capable of receiving the impulses of said tool organism and imparting the same to the governor mechanism. I

3. In combination with a tool organism, a cylinder, a piston therein, a piston-rod for' said piston operatively connected with said tool organism, an auxiliary container in proximity to said cylinder, a main conduit connecting said container with said cylinder and valve-chamber therein, a valve in said chamber and rod therefor extending beyond the chamber, a cam-lever connected with said rod, means carriedby the piston-rod for actuating said cam-lever, a by-pass from said main conduit to said auxiliary container, a valve in said by-pass and rod therefor, a

governor device operativelyconnected withsaid rod, fiearing connecting said overnor device wi said tool organlsm an capable of imparting the impulses of sad tool organism to the governor device, and means for 5 sup lying an operative force to that end of sal cylinder 0 posite to the end communieating with sai auxiliary container.

In testimony whereof I afiix my si ature.

WILSON P. 

